System of distribution.



F. CONRAD.

SYSTEM OF DISTRIBUTION.

APPLICATION FILED UNE 6, 1911.

Patented Sept. 1, 1914.

2 SHEBTSSHEET 1.

INVENTOR 6 M 6W WITNESSES:

ATTORNEY P. CONRAD.

SYSTEM or DISTRIBUTION.

APPLICATION TILED JUNE 6, l9 11.

' Patented Sept. 1,1914.

2 SHEBT8SHEET 2.

8 S ATTdRNEY UNITED STATES PATENT OFFICE.

FRANK CON RAD, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, A. CORPORATION OF PENNSYLVANIA.

SYSTEM OF DISTRIBUTION.

Specification of Letters Patent.

Patented Sept. 1, 1914;.

Application filed June 6, 1911. Serial No. 631,608.

To all whom it may concern:

Be it known that I, FRANK CONRAD, 'a citizen of the United States, and aresident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented a new and useful Improvement in Systems ofDistribution, of which the following is a specification.

My invention relates to systems of dis tribution, and it has for itsobject to provide a practical system of this class which shall be simplein arrangement and shall embody adequate means for automaticallylimiting or restricting the energy delivered to a receiving circuit orto a translating device to a prescribed ultimate value within apredetermined period of time.

It has been a common practice in the prior art to employ a storagebattery in combination with a main source of energy for the purpose ofsupplying variable amounts of current to a receiving circuit, the mainsource of energy. being of sulficient capacity to supply the averageroquired load while the storage battery need only assist the main sourceof energy by carrying the temporary fluctuations and peak loads.

In another application, Serial No. 325,291,

filed by me July 9, 1906, I have set forth a regulator for a storagebattery whereby the load carried by the main source of energy and thevoltage applied to the receiving circuit by the storage battery may bemaintained substantially constant, irrespective of whether the batteryis fully or only partially charged. Such a regulator is employed for thepurpose of causing the battery to carry the peaks and temporary excessesof load and to be charged when the load upon the circuit is less than apredetermined amount. A further purpose of such a regulator is tosupplement the voltage of the battery, which varies with its degree ofcharge, by a variable booster voltage, such that the voltage upon thecircuit may be maintained substantially constant. In the use of thisregulator, it is necessary to periodically observe the specific gravityof the electrolyte of the battery, in order to determine its conditionas regards charge I and to manually adjust the regulator so that themain source of energy will carry an increased proportionof the totalload upon the circuit when the battery is low in charge,

that is, when the specific gravity of its electrolyte is low.

It is a well known fact that, if a storage battery be discharged below apredetermined amount or faster than a predetermined rate, its life andefiicient operation are seriously affected and the cost of maintenanceand attendance is materially increased.

With the end in view of protecting the storage battery from injuriousabuse of the above-mentioned oharacter,.I have devised suitable meansfor automatically adjusting the regulator to eifect increases of load onthe main source of energy when the battery is discharged at apredetermined excessive rate, that is, when the energy supplied by thebattery to the receiving circuit exceeds a predetermined amount within adefinite time interval.

According to my present invention, I employ a regulating device, similarto that set forth in the application hereinbefore mentioned, whichoperates in substantially the Same manner and for the same purposeFurthermore, I provide an integrating wattmeter in the storage batterycircuit which is adapted to integrate the power delivered thereby to thereceiving circuit and, by means of a suitable clock mechanism, thewattmeter is periodically operatively associated with a rheostaticdevice which is connected in one of the regulator circuits in suchmanner that changes in the adjustment of the regulator may be effectedin accordance with the amount of power supplied by the storage batterywithin a given time.

As a modification of the embodiment of my invention hereinbeforeoutlined, I conlighting companies to base their charges, not i only uponthe average demand required bythe customer, but also upon a socallcdpcalr or maximum demand basis.

Heretofore, various devices have been employed for the purpose ofregistering and recording these maximum demands for a predeterminedshort interval of time in each hour, and ,the rate is generallydetermined upon an average of these recorded maximum demand figures. Insome cases, however, power is sold with the stipulation that if anyrecorded peak demand exceeds a prescribed ultimate value, a higher andpermanent average peak rate will be established. It is evident,therefore, that it is of the utmost importance for the customer to keephis peak demand within the prescribed ultimate limit, and for thispurpose, I intend the modified embodiment of my invention, which isarranged to give a-suitable warning when the power consumption for apredetermined interval of time is dangerously near the ultimate limitand to automatically disconnect the receiving circuit or translatingdevice from the source oi energy when the prescribed limit is reached.In this modification, the protecting means is connected. and operated inthe same manner that it would be if employed in connection with astorage battery and its associated regulator, except that, in lieu ofthe rheostatic device, which adjusts the regulator to reduce the loadupon the battery, a switching device is employed which is adapted tooperate a warning signal and subsequently to cause the trip coil of themain circuit interrupter to be energized, whereby the entire load uponthe source of energy is thrown OK.

My invention may best be understood by reference to the accompanyingdrawings, in which Figure 1 is a diagrammatic View of =1 system ofdistribution which embodies my invention and Fig. 2 is a diagrammaticview of a modification thereof.

Referring to Fig. 1, an electrical circuit 1 -2, to which a variableload, represented by translating devices 3, is connected, is sup pliedwith energy from a main generator 1 and a storage battery 5, the latterbeing connected to the'circuit in series with armature 6 of a boostergenerator 7.

' cuit of substantially constant potential.

The resistances 13 and 14 are adapted to lie-alternately shunted bymeans of a regulating device to be hereinafter described, the efi'ect ofsuch shunting being to cause the one-or the other of the auxiliary fieldmagnet windings 11 and 12 of the exciter 9 to predominate in itsmagnetizing efiect.

The ampere turns of the auxiliary field magnet windings 11 and 12 aresuch'that mosses the polarity of the eXciter is dependent upon which ofthe windings predominates in its magnetizing effect. For example, if theresistance 13 is shunted, field magnet winding 11 predominates in itsmagnetizing etlect and the voltage of the exciter 9 will be in such adirection that the voltage of the booster 7 will supplement that of thebattery 5; whereas, if the resistance 1+1 is shunted the ,eiiect of thewinding 12 predominates and the voltage of the booster opposes that ofthe battery.

The regulating means is substantially like that set forth in myapplication, Serial No. 325,291, hereinbefore mentioned, and in myapplication Serial No. $83,660, filed March 15, 1909, and comprises amain relay device consisting of two pivotally mounted arms 16 and 17 thefree ends of which carry cooperating contact terminals 18 and 19. Thearm 16 is maintained in a substantially horizontal position, by means ofa spring 20, and is adapted to be rotatively moved about its pivotalsupport by means of an electro magnetic actuating device consisting of acoil 21, that is connected between the tor-- niinals of the eXciter 9,and permanent magnets 22, between which the coil 21 is movably disposed.It will be understood that the direction of movement of the coil 21 willdepend upon the direction of the flow of current in the booster fieldcircuit. The circuit connections are so arranged that, when thedirection of current flow in the booster field circuit is such that thebooster voltage z-a pplements that of the battery, coil 21 movesupwardly and the contact terminal 18 approaches the contact terminal 19,and when the direction of current flow in the booster field circuit issuch that the booster ,voltage opposes that of the battery, the coil 21moves downwardly and the terminal 18 recedes from the terminal 19.Movements of the arm 16 may be retarded by means of a dash pot 23, orother suitable means.

The other arm 17 of the relay device is actuated to vary the position ofcontact terminal 19 by means of a movable coil 2-1: that is disposedbetween the poles of permanont magnets 25 and is connected in shunt to aresistance 26 in the circuit conductor 2, so that it is traversed by acurrent which is proportional to the current supplied to the translatingdevices 3 by the generator 4. The weight of the coil 24 is partiallycounterbalanced by an adjustable counterweight 2?, and the direction ofcurrent flow in the coil 21 is such as to tend to rotate the arm 17 in acounter clockwise direction in opposition to the efiect of gravity. Themovements of the arm 17 may also be retarded by a suitable means, suchas a dash pot 28.

The contact terminals 18 and 19 govern the circuit of a magnet winding29 of an auxiliary relay device, that, in turn, governs shunt circuitsto the resistances 13 and 14. The relay device comprises, further, apivotally mounted arm 30 carrying flexibly supported contact terminals31 that operate between, and are adapted to alternately enga ge,stationary contact terminals 32 and 33. The contact terminals 32 and 33are connected respectively to the terminals of the resistances 13 and 14and the arm 30 is connected to the common terminal of said resistances.One of the contact members 31 is normally maintained in engagement withthe contact terminal 32 by means of a spring 34, the tension of whichmay be regulated. The other contact terminal 31 is adapted to be moveddownwardly into engagement with the contact terminal 33, by means of anelectromagnet having'two windings, one of which is the winding 29 andthe other is winding 35, the latter winding being permanently connectedbetween the circuit conductors 1-2.

Under normal operating conditions, the effect of the winding 35 is tomaintain the terminals 31 and 33 in engagement, except when the winding29 is energized by reason of the engagement of terminals 18 and 19, whenthe effects of the windings 35 and 29 neutralize each other. Thespring-34 is then permitted to effect the engagement of contactterminals 31 and 32.

The amount of current that traverses the circuit in shunt to theresistance 26 and which includes the coil 24, is regulated automaticallyby means of a rheostatic device 36, which comprises a sub-divided resistance 37, a stationary contact segment 38 and a plurality of stationarycontact terminals 39 to which said resistance is con-- nected. Therheostatic device 36 further comprises a rotatable member 40 carrying amovable contact terminal 41 which normally is adapted to cooperativelyengage the contact segment 38 and which engages the contact terminals39, under predetermined conditions.

An integrating wattmeter 42, of wellknown construction, is connected, inthe usual manner, to the circuit which supplies energy from the battery5 to the translating devices 3, said wattmeter embodying series coils43, armature 44, damping device 44 and a main shaft 45 that rotates atvariable speeds in accordance with we l-known principles.

The meter shaft 45 is provided with a worm 46 and a eotiperatingworm-wheel 47, by means of which the rotational movement of the shaftmay be imparted to an auxiliary shaft. 48, through the agency of a gearwheel 49, which is fixed to the shaft 48 and an idler gear wheel 50, thelatter be ing adapted to be periodically brought into engagement withthe gear wheels 47 and 49, as will be hereinafter set forth.

The idler gear Wheel 50 is suitably suspended from a movable core member51 of an electromagnet 52 which is adapted to be energized periodicallyfrom the battery 5 through a switching device or clock-mechanism 53.

The switching device 53 comprises an anular contact member 54 ofconducting material and a coiiperating rotatable contact arm 55, theinner portion of the annular member 54 being provided with a pluralityof equally spaced and comparatively nar-' row notches 56, and thecontact arm 55 being rotated at uniform speed. By suitably spacing thenotches 56, the duration of contact between the annular member 54 andthe contact arm 55 may be predetermined.

As shown, the contact arm 55 constitutes the minute hand of a clockmechanism, but those skilled in the art will readily understand that anuniform rate of rotation may be imparted to the contact arm 55 by anyother suitable means.

The auxiliary shaft 48 carries the rotata ble member 40, upon which islocated the movable contact member 41, and said shaft is biased to itsinitial position by means of a spiral spring 57 which is adapted toreset the rheostatic device 36 subsequent to the interruption of thecircuit through the switching device 53 and the disengagement of theidler gear wheel 50. A projection 58 is provided on the rotatable member40 to engage a suitable stop 59 and to restrict, the counter clockwiserotation of the movable member 40 in its resetting operation. In thenormal operation of the system, the storage battery 5 may be subjectedto intermittent periods of charge and discharge, and hence, it isevident that the integrating wattmeter 42 will be rotated in oppositedirections, depending upon the action of the battery. However, it is thepurpose of this invention to control only the discharges of the batteryand, hence, it is necessary to provide such connection between the metershaft 45 and .the gear Wheel 47 that the rotational move ment of thewattmeter will be imparted to the movable contact member 41 through theagency of the gear wheels 47, 49 and 50 only when the watt-meter isoperated in a given direction during periods of. discharge. Suchmechanical connections are well known to those skilled in the art, andit is not deemed necessary to show and describe the structure thereof,as any suitable means for accomplishing thexdesired purpose may beemployed. While the auxiliary shaft 48 is operatively associated withthe shaft 45 of the Wattmeter by means of the idler gear wheel 50, therotatable member 40 and its associated movable contact member 41 arerotated from the meter shaft 45 at variable speeds in propor- :tion tothe amount of power delivered by the battery and passing through thewattmeter, as will be readily understood. By suitably designing ordisposing the contact segments 38 and contact terminals 39 of therheostatic device 36, the sections of the resistance 37 may beautomatically inserted into the circuit which includes the movable coil24 when any predetermined amount of power is delivered by the battery 5to the translating devices 3 within the contact period or time intervalfor which the switching device 53 is designed or adjusted. Whenresistance is thus inserted in circuit with the coil 24, it is evidentthat an increased amount of current must traverse the resistance 26, inorder to cause a sufficient amount of current to traverse the coil 24 toeffect a disengagement of the contact terminals 18 and 19 or to causethe contact terminal 19 to be moved downwardly.

Since the current which traverses the resistance 26 is that which issupplied by the generator 4 to the receiving circuit or translatingdevices 3, the variations of the reslstance 37, through the agency ofthe wattmeter 42, automatically eflects adjustments of the load carriedby the generator 4, whereby the amount of energy delivered to thereceiving circuit by the storage battery 5 is reduced. Thus,predetermined injurious and excessive battery discharges areautomatically prevented.

Tnasmuch as the regulating device pertains to my invention onlyindirectly as it performs a necessary function in the operation of thesystem, and, inasmuch as its construction and mode of'operation are setforth in detail in my application Serial No. 483,660, T do not considerit advisable to present any further discussion of the mode of operation.

In so far as the present application is concerned, it is suficient tounderstand that the insertion of the resistance 37 into the circuitwhich includes the movable coil 24 au tomatically efl'ects suchadjustments in the regulating .device that the load upon the maingenerator 4 is increased while the load supplied by the storage batteryis correspondingly decreased.

Assuming the translating devices 3 to be operating under normalconditions, the reg ulating device to be performing its intendedfunction of maintaining the load upon the generator 4 constant, and thevarious circuit connections and devices to occupy the positions shown,the operation of the tem is as follows: It will be -noted that themovable contact arm 55 of the clock mechanism 53 registers with one ofthe notches 56 in the annular contact member 54 and,

hence, the electromagnet 52 is deenergized and the rotatable member 40,which carries the movable contact member, 41, is disconnected from theshaft 45 of the wattmeter 42.

nioaeae As the contact arm 55 passes over the notches 56, which requiresan inappreciable amount of time in comparison with the duration of thecontact interval, an engagement with the annular contact member 54 iseffected, thereby establishing an energizing circuit through theelectromagnet 52 and causing the idler gear wheel 50 to be brought intooperative engagement with the gear wheels 47 and 49. Thus, the rotatablemember 40 is operatively associated with the shaft 45 of the wattmeterand the movable contact member 41 may therefore be rotated in'aclockwise direction in accordance with the amount of power delivered bythe storage battery 5 to the translating devices 3, through thewattmeter 42. If the storage battery 5is discharging and supplyingenergy to the trans lating devices 3, the movable contact member 41,which is associated with the rotatable member 40, is gradually rotatedin a clockwise direction, in accordance with the amount of power passingthrough the wattmeter 42. llf the total energy integrated by thewattmeter within the predetermined time interval be sufficient to causethe movable contact member 41 to engage the first contact terminal 39,the first section of the resistance37 is automatically inserted into thecircuit which includes the movable coil 24. Thus, as hereinbeforeexplained, the regulator is adjusted to cause the generator 4 to take agreater portion of the load while the storage battery 5 is partiallyrelieved of its excessive discharge. In case more energy is deliveredfrom the battery 5 within that particular time interval, the contactmember 41 is caused to successively engage the remaining contactterminals 39, whereby additional sections of the resistance 37 aresuccessively inserted into the regulator circuit and the total load uponthe system is gradually thrown upon the generator 4, in order to preventan excessive and injurious discharge of. the battery 5, as will bereadily understood. When the predetermined time interval has elapsed,the rotatable contact arm 55 of the switching device 53 registers withone of the notches 56 and the energizing circuit through theelectromagnet 52 is interrupted, thereby allowing the idler gear wheel50 to drop out of engagement with the gear wheels 47 and 49. The shaft48 and its associated rotatable member 40 are then immediately returnedto their initial position, by means of the spiral spring 57. In case theamount of power delivered within the'predetermined time interval to thetranslating devices 3 by the storage battery 5 be 'insufiicient to causethe movable contact member 41 is reset to its initial position withoutaffecting the adjustment or operation of the regulator. This cycle ofoperation is periodically repeated in the manner hereinbefore set forth,and excessive and injurious rates of discharge of the battery arethereby prevented.

Reference may now be had to Fig. 2, in which similar parts aredesignated by the same reference characters.

A supply circuit 12 is adapted to deliver energy through a circuitinterrupter 60 and an integrating watt-meter 42 to a plurality oftranslating devices 3, an auxiliary shaft 48 and its associatedrotatable member 40 being adapted to be periodically connected to themeter shaft 45, through the agency of suitable gear wheels 47, 49 and50, and a clock mechanism or switching device 53 in a manner similar tothat hereinbefore set forth in connection with the system shown in Fig.1.

The circuit interrupter 60 may be of any well-known type of constructionand is provided with an auxiliary trip coil 61 which is adapted to beenergized under predetermined conditions by an auxiliary battery '62 orother suitable source of energy.

The construction and mode of operation of the integrating wattmeter 42,the switching device 53 and the mechanism by which the movable contactmember 41 is rotated in accordance with the amount of power traversingthe watt-meter 42, are similar to those hereinbefore set forth in detailand no 35 further description of the same will be given.

The contact members 38 and 39 are adjustable in position and may be solocated that engagement with the movable contact member 41 occurs whenany predetermined a0 amounts of power are consumed by the translatingdevices 3 within the contact period or time interval for which theswitching device 53 is designed.

Assuming the translating devices 3 to be- 45 operating under normalconditions and the various parts of the apparatus to occupy thepositions shown, the operation of the system is as follows: It will benoted that the contact arm 55 of the switching device 53 is not -'50 inengagement with the annular contact member 54, and, hence, theelectromagnet 52 is denergized and the rotatable member 40 is notoperatively associated with the shaft of the wattmeter 42. However, asthe con- 55 tact arm 55 moves into engagement with the annular contactmember 54, a circuit is completed through the energizing winding of theelectromagnet 52 and the gear wheel 50 is raised into engagement withthe gear wheels 60 47 and 49, thereby establishing an operativeconnection between the shaft 48 and the wattmeter 42. The movablecontact member 41 is, therefore, rotated in a counter clock-wisedirection, in accordance with the amount of 65 power consumed by thetranslating devices/ 3 and integrated by the wattmeter '42. If the powerconsumption within the given time interval is sufficient to cause theengagement of the contact member 41 and the contactmember 38, a circuitwhich includes the contact members 41 and 38 and the signal lamp G3, isestablished from the battery 62. Thus, energy is supplied to the lamp63, which constitutes a warning signal to indicate that the total amountof integrated power is dangerously near the ultimate prescribed peakdemand for which the-apparatus is adjusted. If the consumption of powerwithin the predetermined time interval is sufficient to cause engagementof the movable contact member 41 with the stationary contact terminal39, a circuit, which includes the contact members 41 and 39 and the tripcoil 61 of the circuit interrupter 60, is established from the battery62. Energy is thus supplied to the trip coil 61 which trips open thecircuit interrupter 60, accordto well-known practice and therebydiscontinues the power consumption andv prevents an excessive ultimatepeak demand. If the contact period or predeterminedtime interval elapsesbefore the movable contact member 41 comes into engagement with thecontact terminal 39, an interruption of the circuit through the windingof the electromagnet 52 is effected by means of the switching device 53and the idler gear wheel is dropped out of engagement with the gearWheels 47 and 49. The spiral spring 57 then returns the rotatable member40 and its associated contact member 41 to the initial position. Thiscycle of operation continues periodically in the manner hereinbefore setforth until an excessive amount of power is consumed and .thetranslating devices are automatically disconnected from the source ofenergy, as hereinbefore described.

Although I have set forth my invention -as embodying systems ofdistribution having specific circuit connections and arrangement andlocation of parts, it is evident that various modifications may beeffected therein without departing from the spirit and scope of myinvention, and I desire that only such limitations shall be imposed asare indicated in the appended claims.

I claim as my invention:

1. The combination with an electric circuit and an integratingwattmeter, of a movable member, means for periodically associating saidmovable: member with said wattmeter, and means dependent upon themovement of said movable member for effecting changes in said electriccircuit.

2. The combination with an electric circuit and an integratingwattmeter, of a movable member biased to its initial position, means foroperatively associating said movable member withsaid wattmeter, andmeans associated with said movable member and dependent uponthe degreeof movement thereof for efiecting changes in said electric circuit.

3. The combination with a shaft that rotates at variable speeds and amovable member biased to its initial position and adapted to beperiodically associated with said shaft, of a circuit, and acircuit-controlling device associated with said movable member andadapted to effect changes in said circuit when said member is moved apredetermined amount.

4. The combination with a shaft that rotates at variable speeds, arotatively movable member biased to its initial position and adapted tobe periodically associated with said shaft for given intervals of time,of a circuit, and a circuit-controlling device associated with saidrotatively movable member and adapted to effect changes in said circuitwhen said member is moved a predetermined amount.

5. The combination with an integrating wattmeter, a rotatively movablemember biased to its initial position and adapted to be moved inproportion to the amount of energy periodically passing through saidwattmeter, and electromagnetic means for periodically associating saidmovable member with said wattmeter, of an electricpircuit, and meansassociated with said movable member and dependent upon a predeterminedamount of movement thereof for effecting changes in said circuit.

6. The combination with an electric circuit, a circuit-controllingmeans, and 2. watt meter device connected to said circuit, of means foroperating said circuit-controlling means when the power consumed duringa predetermined interval of time exceeds a predetermined amount.

7. The combination with an electrical circuit, a wattmeter deviceconnected thereto, and a. circuit-controlling device, of means forcausing said circuit controlling device to effect changes in saidcircuit when the electrical energy supplied to said wattmeter deviceduring a predetermined period exceeds a predetermined amount.

8. The combination with a wattmeter device and a circuit-controllingdevice, of mechanical means for effecting operative engagement of saidcircuit-controlling device and said wattmeter device, and means forperiodically controlling the action of said mechanical means.

9. The combination with a supply circuit, translating means, and awattmeter device, of means dependent upon time and upon the amount ofpower traversing said wattmeter device for effecting reductions of powerin said supply circuit.

10. The combination with a supply circuit, a translating device, and anintegrating wattmeter, of a rotatively movable member adapted to beoperatively associated with said wattmeter, a clock mechanism adapted toeffect said association for successive predetermined intervals of time,and electrical means dependent upon the degree of movement of saidmember for efiecting changes in said supply circuit when the powertraversing said wattmeter during any interval exceeds a predeterminedvalue.

11. The combination with an electric circuit, a translating device, anda wattmeter device, of a rotatively movable member adapted to beoperatively associated with said wattmeter device, means forsuccessively effecting said association for predetermined intervals oftime, and means associated with said movable member for effectingreductions of power in said circuit when the power traversing saidwattmeter during any interval exceeds a predetermined value. v

12. The combination with a storage battery and means for causing thesame to charge and discharge, of means embodying a wattmeter device forrestricting the rate of discharge to a predetermined value.

13. The combination with a translating device, a generator and a batteryconnected in multiple, and adapted to supply energy thereto, of meansembodying a wattmeter device and a switching device actuated thereby forgradually shifting the load upon said generator when the rate ofdischarge of said battery exceeds a predeten' mined amount.

l t. The combination with an electric circuit, a generator supplying thesame, and a battery associated with said circuit, of means embodying awattmeter device and a switching device cooperating therewith forregulating the battery to prevent the energy delivered thereby to theelectric circuit from exceeding a predetermined value within apredetermined time interval.

15. The combination with a receiving circuit, a generator and a batterysupplying energy thereto, and a regulating device having cooperatingenergizing coils for maintaining a predetermined load upon saidgenerator, of means embodying a wattmeter device and a switching deviceassociated with said battery and dependent upon the rate of dischargethereof for automatically controlling the energization of the coils ofsaid regulating device.

16. The combination-with a storage battery and a translating device, ofautomatic means embodying a voltage regulating device, a switchingdevice in circuit therewith and an actuating device therefor dependentupon time and upon the amount of energy delivered by said battery forpreventing said battery from discharging in excess of a predeterminedrate.

17. The combination with a receiving circuit, a generator and a batteryadapted to supply energy thereto, and a regulating device iormaintaining a constant load upon said generator and for causing saidbattery to charge and discharge, of a wattmeter mechanism connected insaid battery circuit, and a rheostatic device adapted to be periodicallyassociated therewith for automatically effecting changes in theoperation of said regulating device when the energy discharged from saidbattery exceeds a predetermined amount in a given time interval.

18. The combination with an electric circuit, a storage battery, abooster associated therewith, and an exciter for said booster, of meansfor governing the direction and value of the electromotive force of saidbooster, said means comprising two cooperating contact-carrying members,one of FRANK CONRAD. Witnesses:

F. D. HALLOCK, B. B. HrNEs.

